1. Field of the Invention
This invention relates to a thermoplastic, hydrophilic, segmented, copolyesterether elastomer. More particularly, the invention concerns such an elastomer having certain soft segments that are long chain ester units formed from poly(alkylene oxide) glycols and certain hard segments that are short chain ester units formed from diols and dicarboxylic acids, esters or ester-forming derivatives. The elastomers, when swollen with imbibed water, are particularly suited for use in artificial fishing lures, wet wound-dressings, and the like. 2. Description of the Prior Art
Shivers, U.S. Pat. No. 3,023,192, discloses hydrophilic, thermoplastic, segmented copolyetherester elastomers having soft and hard segments. The soft segments constitute about 35 to about 75% of the elastomer weight and are derived from a poly(alkylene oxide) glycol, such as poly(ethylene oxide) glycol, poly(propylene oxide) glycol, poly(tetramethylene oxide) glycol and mixtures thereof, preferably a poly(tetramethylene oxide) glycol. The hard segments constitute 65 to 25% of the elastomer and are derived from an aromatic dicarboxylic acid, such as terephthalic, isophthalic, bibenzoic, naphthalene dicarboxylic, and mixtures thereof, preferably terephthalic acid. Shivers discloses at column 10, lines 45-68, that many of his elastomers are hydrophilic. However, the polyetherester elastomers disclosed by Shivers, are inadequate for certain specialty applications, such as those that require the elastomer to imbibe large quantities of water and still have adequate elasticity and strength. An object of this invention is to provide a copolyetherester elastomer that overcomes or at least significantly reduces the aforementioned inadequacies.